EtherChannel Manual Configuration

An EtherChannel is a group of links that work together as a single link. There are two ways to configure an EtherChannel: Static and Dynamic. In the static method, we manually configure an EtherChannel. In the Dynamic configuration, we configure an EtherChannel protocol, and then the protocol configure and manage the EtherChannel. This tutorial explains the static or manual method of EtherChannel configuration.

Commands/Steps for a Manual EtherChannel Configuration

The following interface configuration mode command creates a new EtherChannel if an EtherChannel with the specified number does not exist and adds the interface to the EtherChanel. If an EtherChannel with the specified number exists, it adds the interface to the EtherChannel.

Switch(config-if)#channel-group [number] mode on

You must run the above command on all interfaces you want to add to the EtherChannel.

EtherChannel Packet Tracer Example

Create a packet tracer lab, as shown in the following image.

lab for packet tracer

Download the packet tracer lab

STP is the default on all Cisco switches. It automatically finds loops and block ports that cause the loops.

lab with disabled ports

We can verify it by viewing the STP port states. The show spanning-tree command displays the STP port states.

show spanning-tree

As we can see in the above output, STP blocked F0/2, F0/3, and F0/4 ports to remove loops. Since STP has blocked these ports, the switch can't use them to forward frames.

Access the interface configuration mode of F0/1, F0/2, F0/3, and F0/4 interfaces and run the following command.

You can use any channel number between 1 to 6. The channel number must be the same on all interfaces you want to put in a channel group. You can add up to eight ports to a single EtherChannel.

channel-group mode on

Use the show spanning-tree command again to view the STP ports' states.

show spanning-tree command

As we can see in the above output, there is only one interface instead of four. It is a pool of all four interfaces. STP treats this pool as a single interface. If any interface from this pool fails, it does not trigger STP. STP reruns its algorithm only when all interfaces inside the pool fail.

On a physical Cisco switch or any advanced simulator software such as GSN3, you can use the show etherchannel [number] summary command to view detailed information about specified EtherChannel. Packet Tracer supports a stripped-down version of this command.

channel group command

The following image shows the output of the show spanning-tree command on the second switch.

show spanning-tree comamnd

The following image shows the configuration steps for the EtherChannel on the second switch.

channel-group mode on

The following image shows the output of the show spanning-tree command on the second switch after the EtherChannel Configuration.

show etherchannel

Download the packet tracer lab with the configuration

This tutorial is the second part of the tutorial "EhterChannel Concepts and Configurations Explained.". Other parts of this series are the following.

Chapter 01 EtherChannel Basic Concepts Explained

Chapter 03 Port Aggregation Protocol (PAgP) Explained

Chapter 04 Link Aggregation Control Protocol (LACP) Explained

Chapter 05 EtherChannel Load Distribution Explained

Conclusion

EtherChannel is a group of ports that works as a single port on the switch. You can use EtherChannels for various reasons. The two most common reasons are redundancy and load balancing. The etherchannel-group [number] mode on command in interface configuration mode adds the interface in the specified EtherChannel group. A switch can have six EtherChannels. An EtherChannel can have up to eight ports in it.

ComputerNetworkingNotes CCNA Study Guide EtherChannel Manual Configuration